arXiv subjects

Abdul Mannan

Publications and source records attributed to Abdul Mannan.

3 recordsLinked to original sources

arXiv2025

Transverse envelope dynamics of beam slices in a uniform charged ellipsoidal model of the plasma bubble regime

We consider a pair of driver/witness electron bunches propagating in an ionized gas background a configuration similar to the one produced in a capillary discharge where a plasma oscillation has been excited by a driving pulse. We assume as in the plasma nonlinear regime that the plasma electrons behind the driver are completely expelled and an ellipsoidal cavity filled with ions only is formed. The fields are linear in both longitudinal and transverse directions, at least in the region of interest for particle acceleration, as the one produced by a uniform ion distribution within a uniformly charged ellipsoidal volume. The fields produced by the ions and experienced by a witness electron beam are purely electrostatic, being the ions at rest in the laboratory frame on the time scale of interest and it can be represented with the field distribution produced by a 3D charged ellipsoidal. The energy spread and emittance degradation has been studied by slicing the bunch in an array of cylinders and solving envelope equations for each bunch slice. The properties of transverse envelope and emittance oscillations and energy spread degradation have been analyzed together with the related matching conditions for optimal transport and acceleration.

physics.plasm-ph↗

arXiv2021

Solitary waves and double layers in complex plasma media

A complex plasma medium (containing Cairns nonthermal electron species, adiabatically warm inertial ion species, and stationary positively charged dust (PCD) species (making a plasma system very complex) is considered. The effects of PCD species, nonthermal electron species, and adiabatic ion-temperature on ion-acoustic (IA) solitary waves (SWs) and double layers (DLs) are investigated by the pseudo-potential approach, which is valid for the arbitrary amplitude time-independent SWs and DLs. It is observed that the presence of the PCD species reduces the phase speed of the IA waves, and consequently supports the IA subsonic compressive SWs in such electron-ion-PCD plasmas. On the other hand, the increase in both adiabatic ion-temperature and the number of nonthermal or fast electrons causes to reduce the possibility for the formation of the subsonic SWs, and thus convert subsonic SWs into supersonic ones. It is also observed that after at a certain value of the nonthermal parameter, the IA supersonic SWs with both positive and negative potentials as well as the DLs with only negative potential exist. The applications of the work in space environments (viz. Earth's mesosphere, cometary tails, Jupiter's magnetosphere, etc.) and laboratory devices, where the warm ion and nonthermal electron species along with PCD species have been observed, are briefly discussed.

physics.plasm-ph↗

arXiv2020

Dust-acoustic wave electrostatic and self-gravitational potentials in an opposite polarity dusty plasma system

An opposite polarity dusty plasma system (containing a few micron size massive opposite polarity dust species and singly charged ion species following Boltzmann law) is considered. The nature of dust-acoustic (DA) wave electrostatic and self-gravitational potentials are correctly found by the numerical analysis of two coupled second-order nonlinear differential equations for electrostatic and self-gravitational potentials associated with the DA waves in such an opposite polarity dusty plasma medium. These coupled nonlinear differential equations are derived from the continuity and momentum equations for positive and negative dust species, and the Boltzmann law for ion species. The basic features of the DA wave self-gravitational potential are compared with that of the DA wave electrostatic potential. The relevance of our results to space and laboratory opposite polarity dusty plasma systems is mentioned.

physics.plasm-ph↗